Malignant Transformation of Recurrent Synovial Chondromatosis: A Case Report and Review.

John W Urwin,Ronnie Sebro,Kumarasen Cooper

doi:10.7759/cureus.5839

Abstract

Chondrosarcoma is the second most common primary malignant bone tumor. While the majority arrive de novo, a minority arise from malignant transformation of benign neoplasms, such as osteochondromas. Rarely, chondrosarcomas have been found to originate from other preexisting lesions, such as synovial chondromatosis.A 44-year-old male with a history of a spinal osteochondroma presented with one year of left hip pain and decreased range of motion. On examination, he had a palpable, irregular fullness in the left groin that was minimally tender to palpation. Radiographs and CT of the hip showed extensive soft tissue calcifications and erosion of the femoral neck. The lesion was debulked surgically and histologically diagnosed as synovial osteochondromatosis with no evidence of atypia or cellularity.One year later, his residual disease progressed and resulted in increasingly limited range of motion. He underwent left total hip arthroplasty with simultaneous debulking and the lesion was once again diagnosed as synovial osteochondromatosis.Two months postoperatively, the patient developed a new focus of calcification around the hip joint that was thought to be recurrent disease. Six months later, due to worsening symptoms, he underwent a repeat CT scan. This scan demonstrated extensive intra-articular disease extending into the iliopsoas bursa and around total hip arthroplasty, as well as a new soft tissue nodule with foci of calcification in the left gluteus maximus. The new lesion was debulked surgically and diagnosed as a grade 1 chondrosarcoma.Chondrosarcoma arising from synovial chondromatosis is a rare presentation of the second most common primary malignant bone tumor. It typically presents as an indolent, slowly growing painful mass of large joints in middle aged men. Conventional radiography shows punctate opacities, while MRI and CT reveal diffuse soft tissue calcification and cortical erosion. Low-grade chondrosarcomas are treated with intralesional curettage and adjuvant therapy, while higher grade chondrosarcomas are treated with wide, en bloc excision. Malignant transformation should be considered in any patient presenting with worsening symptoms and a history of a benign bony lesion.

Highlights

Synovial chondromatosis was first described by Ambrose Pare in 1558 and Laennic in 1813 [1,2]
Secondary synovial chondromatosis is more common than primary synovial chondromatosis and presents later in life, typically during the fifth or sixth decade of life [4]
We present a case of synovial chondromatosis with subsequent malignant degeneration into a grade 1 chondrosarcoma of the hip in a 44-year-old male patient with hip pain

Summary

Introduction

Synovial chondromatosis was first described by Ambrose Pare in 1558 and Laennic in 1813 [1,2]. Primary synovial chondromatosis typically presents indolently as a slow-growing intra-articular masses of large joints It can cause joint pain, decreased range of motion, and joint stiffness, and often the diagnosis is suggested from radiographs [8]. His radiographs of the left hip (Figures 2 and 3) showed extensive soft tissue calcifications surrounding the hip joint associated with erosion of the femoral neck and mild left hip degenerative changes. White arrows point to extensive soft tissue calcifications surrounding the hip joint associated with erosion of the femoral neck and mild degenerative changes. The CT scan demonstrated extensive intra-articular disease extending into the iliopsoas bursa (Figure 6) and around total hip arthroplasty as well as a new soft tissue nodule with foci of calcification in the left gluteus maximus, consistent with an additional focus of disease (Figure 7). The final histological diagnosis from the excised tumor was grade 1 chondrosarcoma arising from synovial chondromatosis

Discussion

Disclosures

Findings

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